Arrangement for a Screw Compressor of a Utility Vehicle

ABSTRACT

An arrangement for a screw compressor of a utility vehicle has at least one housing part of the screw compressor and a baffle. The housing component has at least three baffle receptacle recesses, wherein at least one baffle receptacle recess is arranged outside an imaginary line connecting the two other baffle receptacle recesses. The baffle has at least three fingers which, in the assembled state of the arrangement, are each inserted in a baffle receptacle recess associated with the respective finger.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT International Application No.PCT/EP2017/073576, filed Sep. 19, 2017, which claims priority under 35U.S.C. § 119 from German Patent Application No. 10 2016 011 444.4, filedSep. 21, 2016, the entire disclosures of which are herein expresslyincorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to an arrangement for a screw compressorof a utility vehicle, comprising at least one housing component of thescrew compressor and a baffle plate.

Screw compressors for utility vehicles are already known from the priorart. Such screw compressors are used, for example, to provide thecompressed air required for the brake system of the utility vehicle.

In this context, in particular oil-filled compressors, in particularalso screw compressors, are known, in the case of which it is necessaryto regulate the oil temperature. This is generally realized by virtue ofan external oil cooler being provided which is connected to theoil-filled compressor and to the oil circuit via a thermostat valve.Here, the oil cooler is a heat exchanger which has two mutually separatecircuits, wherein the first circuit is provided for the hot liquid, thatis to say the compressor oil, and the second circuit is provided for thecooling liquid. As cooling liquid, use may for example be made of air,water mixtures with an antifreeze, or another oil.

This oil cooler must then be connected to the compressor oil circuit byway of pipes or hoses, and the oil circuit must be safeguarded againstleakage.

This external volume must furthermore be filled with oil, such that thetotal quantity of oil is also increased. The system inertia is thusincreased. Furthermore, the oil cooler must be mechanically accommodatedand fastened, either by way of brackets situated in the surroundings orby way of a separate bracket, which necessitates additional fasteningmeans and also structural space.

U.S. Pat. No. 4,780,061 has already disclosed a screw compressor with anintegrated oil cooling arrangement.

Furthermore, DE 37 17 493 A1 discloses a screw compressor installationwhich is arranged in a compact housing and which has an oil cooler onthe electric motor of the screw compressor.

A generic screw compressor is already known for example from DE 10 2004060 417 B4.

In order to be able to better control the movements of the oil in thescrew compressor itself even during driving operation of the utilityvehicle, it is desirable firstly to enable the oil to reach anywhere inthe screw compressor itself for lubrication purposes but secondly tocontrol the oil sump in terms of its movement.

It is therefore the object of the present invention to advantageouslyfurther develop an arrangement for a screw compressor of a utilityvehicle of the type mentioned in the introduction, in particular suchthat the assembly of the screw compressor can be simplified and improvedoverall.

This object is achieved according to the invention by an arrangement fora screw compressor of a utility vehicle having the claimed features.Provision is made for an arrangement for a screw compressor of a utilityvehicle to comprise at least one housing component of the screwcompressor and a baffle plate, wherein the baffle plate is, in theassembled state, inserted in clamped fashion in the housing component.

The invention is based on the underlying concept of the fastening of thebaffle plate in the housing component of the screw compressor beingrealized in a simple and reliable manner. This is realized in particularby virtue of the baffle plate being held with clamping action in thehousing. For this purpose, a mere insertion of the baffle plate into thehousing component is sufficient to permit a reliable fastening.

The housing component advantageously has at least three baffle platereceiving apertures, wherein at least one baffle plate receivingaperture is arranged outside an imaginary line which connects the twoother baffle plate receiving apertures, and wherein the baffle plate hasat least three fingers which, in the assembled state of the arrangement,are inserted in each case into a baffle plate receiving apertureassigned to the respective finger. Owing to the fact that the baffleplate receiving apertures are not in alignment and also do not lie on aline, this arrangement results in a bending force being exerted on thebaffle plate during the insertion process, such that said baffle plateis held in clamped fashion in the housing component. The baffle plate isthus held with clamping action in the housing component and can, afterbeing inserted into the baffle plate receiving apertures, be heldsecurely therein owing to the bending force exerted as a result of theshaping and arrangement of the baffle plate receiving apertures. Fallingout is hereby reliably prevented. Due to the fastening by way of baffleplate receiving apertures and correspondingly associated fingers in thebaffle plate, simple production is made possible. Due to the insertionof the baffle plate into the baffle plate receiving apertures, theassembly process is furthermore made relatively straightforward. Evenautomated fitting and assembly is conceivable and possible.

Provision may furthermore be made for the housing component to be therotor housing of the screw compressor. In this context, it isadvantageous in particular for the baffle plate to be arranged below therotors (in relation to the assembled state).

It is however basically also contemplated for the housing component tobe the housing cover of the screw compressor. By inserting the baffleplate into a first housing component of the housing, such as for examplethe housing cover, it is made possible for the fastening to be realizedonly in one single housing component. Since the baffle plate is herebyalready securely held, a fastening in another housing component of thehousing of the screw compressor is no longer necessary. This factself-evidently also applies analogously to an arrangement of the baffleplate and a fastening of the baffle plate in the rotor housing.

Provision may furthermore be made whereby the middle of the three baffleplate receiving apertures is arranged outside the imaginary line thatconnects the two other baffle plate receiving apertures. In this way, itis made possible to realize relatively simple clamping because, in themiddle region, the bending force is formed which then serves forclamping of the baffle plate in the baffle plate receiving apertures orin the housing component of the screw compressor. The bending forcesrequired for the assembly process, which can be imparted for thispurpose, are furthermore relatively easy to apply because the baffleplate has to be bent in the middle, and then an insertion can beperformed relatively easily.

The fingers of the baffle plate may be substantially in alignment in thenon-inserted and non-assembled state. It is contemplated in particularfor the baffle plate, in the non-bent state, to be a relatively simpleflat non-bent or planar plate. By means of such an arrangement,inexpensive manufacture is made possible, and an easy application of therequired bending forces for the insertion of the baffle plate into thehousing component is achieved. In particular, provision may be madewhereby the baffle plate is, in the inserted and assembled state, as aresult of the insertion of the fingers into the respectively associatedbaffle plate receiving apertures, bent such that the baffle plate isheld braced with clamping action in the housing component. By way of thebraced holding with clamping action, it is reliably achieved that thebaffle plate is blocked in the housing component merely as a result ofthe insertion of its three fingers into the associated baffle platereceiving apertures. Owing to the fact that the bending promotes thebraced holding with clamping action, a self-securing holding action isachieved in this way.

The fingers of the baffle plate may all be arranged at one edge of thebaffle plate. Simple manufacture is hereby achieved. For the insertionof the baffle plate in the housing component, a single movement is thussufficient, and an additional adjustment or insertion into other housingcomponents is not necessary.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of one ormore preferred embodiments when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional drawing through an exemplary screwcompressor according to the invention.

FIG. 2 is a perspective view of the rotor housing of the screwcompressor as per FIG. 1.

FIG. 3 is a perspective view of the baffle plate as per FIG. 2.

FIG. 4 is a detailed plan view of the baffle plate receiving aperturesin the rotor housing as per the exemplary embodiment in FIG. 2.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows, in a schematic sectional illustration, a screw compressor10 in the context of an exemplary embodiment of the present invention.

The screw compressor 10 has a fastening flange 12 for the mechanicalfastening of the screw compressor 10 to an electric motor (not shown inany more detail here).

What is shown, however, is the input shaft 14, by which the torque fromthe electric motor is transmitted to one of the two screws 16 and 18,specifically the screw 16.

The screw 18 meshes with the screw 16 and is driven by means of thelatter.

The screw compressor 10 has a housing 20 in which the main components ofthe screw compressor 10 are accommodated.

The housing 20 is filled with oil 22.

At the air inlet side, an inlet connector 24 is provided on the housing20 of the screw compressor 10. The inlet connector 24 is in this casedesigned such that an air filter 26 is arranged at said inlet connector.Furthermore, an air inlet 28 is provided radially on the air inletconnector 24.

In the region between the inlet connector 24 and the point at which theinlet connector 24 joins to the housing 20, a spring-loaded valve insert30 is provided, which is designed here as an axial seal.

The valve insert 30 serves as a check valve.

Located downstream of the valve insert 30, an air feed channel 32 feedsthe air to the two screws 16, 18.

At the outlet side of the two screws 16, 18, an air outlet pipe 34 witha riser line 36 is provided.

In the region of the end of the riser line 36, a temperature sensor 38is provided by which the oil temperature can be monitored.

Also provided in the air outlet region is a holder 40 for an airdeoiling element 42.

In the assembled state, the holder 40 for the air deoiling element hasthe air deoiling element 42 in the region facing toward the base (asalso shown in FIG. 1).

Also provided, in the interior of the air deoiling element 42, is acorresponding filter screen or known filter and oil separation devices44, which will not be specified in any more detail.

In the central upper region in relation to the assembled andoperationally ready state (that is to say as shown in FIG. 1), theholder for the air deoiling element 42 has an air outlet opening 46which lead to a check valve 48 and a minimum pressure valve 50. Thecheck valve 48 and the minimum pressure valve 50 may also be formed inone common combined valve.

The air outlet 51 is provided downstream of the check valve 48.

The air outlet 51 is generally connected to correspondingly knowncompressed-air consumers.

In order for the oil 22 that is situated and separated off in the airdeoiling element 42 to be returned into the housing 20, a riser line 52is provided which has a filter and check valve 54 at the outlet of theholder 40 for the air deoiling element 42 at the transition into thehousing 20.

A nozzle 56 is provided, downstream of the filter and check valve 54, ina housing bore. The oil return line 58 leads back into approximately thecentral region of the screw 16 or of the screw 18 in order to feed oil22 thereto again.

An oil drain screw 59 is provided in the base region, in the assembledstate, of the housing 20. By means of the oil drain screw 59, acorresponding oil outflow opening can be opened, via which the oil 22can be drained.

Also provided in the lower region of the housing 20 is the attachmentpiece 60 to which the oil filter 62 is fastened. Via an oil filter inletchannel 64, which is arranged in the housing 20, the oil 22 is conductedfirstly to a thermostat valve 66.

Instead of the thermostat valve 66, it is possible for an open-loopand/or closed-loop control device to be provided by which the oiltemperature of the oil 22 situated in the housing 20 can be monitoredand set to a setpoint value.

Downstream of the thermostat valve 66, there is then the oil inlet ofthe oil filter 62, which, via a central return line 68, conducts the oil22 back to the screw 18 or to the screw 16 again, and also to theoil-lubricated bearing 70 of the shaft 14. Also provided in the regionof the bearing 70 is a nozzle 72, which is provided in the housing 20 inconjunction with the return line 68.

The cooler 74 is connected to the attachment piece 60, as will bediscussed in more detail below in FIGS. 2 to 4.

In the upper region of the housing 20 (in relation to the assembledstate), there is situated a safety valve 76, by which an excessivelyhigh pressure in the housing 20 can be dissipated.

Upstream of the minimum pressure valve 50, there is situated a bypassline 78, which leads to a relief valve 80. Via the relief valve 80,which is activated by way of a connection to the air feed 32, air can bereturned into the region of the air inlet 28. In this region, there maybe provided a ventilation valve (not shown in any more detail) and alsoa nozzle (diameter constriction of the feeding line).

Furthermore, approximately at the level of the line 34, an oil levelsensor 82 may be provided in the outer wall of the housing 20. The oillevel sensor 82 may for example be an optical sensor, and may bedesigned and configured such that, on the basis of the sensor signal, itcan be identified whether the oil level during operation is above theoil level sensor 82 or whether the oil level sensor 82 is exposed, andthus the oil level has correspondingly fallen.

In conjunction with this monitoring, it is also possible for an alarmunit to be provided which outputs or transmits a corresponding errormessage or warning message to the user of the system.

The function of the screw compressor 10 shown in FIG. 1 is as follows.

Air is fed via the air inlet 28 and passes via the check valve 30 to thescrews 16, 18, where the air is compressed. The compressed air-oilmixture, which, having been compressed by a factor of between 5 and 16downstream of the screws 16 and 18, rises through the outlet line 34 viathe riser pipe 36, and is blown directly onto the temperature sensor 38.

The air, which still partially carries oil particles, is then conductedvia the holder 40 into the air deoiling element 42 and, if thecorresponding minimum pressure is attained, passes into the air outletline 51.

The oil 22 situated in the housing 20 is kept at operating temperaturevia the oil filter 62 and possibly via the heat exchanger 74.

If no cooling is necessary, the heat exchanger 74 is not used and isalso not activated.

The corresponding activation is performed by way of the thermostat valve66. After purification in the oil filter 64, oil is fed via the line 68to the screw 18 or to the screw 16, and also to the bearing 72. Thescrew 16 or the screw 18 is supplied with oil 22 via the return line 52,58, and the purification of the oil 22 takes place here in the airdeoiling element 42.

By use of the electric motor (not shown in any more detail), whichtransmits its torque via the shaft 14 to the screw 16, which in turnmeshes with the screw 18, the screws 16 and 18 of the screw compressor10 are driven.

By use of the relief valve 80 (not shown in any more detail), it isensured that the high pressure that prevails for example at the outletside of the screws 16, 18 in the operational state cannot be enclosed inthe region of the feed line 32, and that, instead, in particular duringthe start-up of the compressor, there is always a low inlet pressure, inparticular atmospheric pressure, prevailing in the region of the feedline 32. Otherwise, upon a start-up of the compressor, a very highpressure would initially be generated at the outlet side of the screws16 and 18, which would overload the drive motor.

FIG. 2 shows, in a perspective view, the arrangement for the screwcompressor 10 of the utility vehicle having the at least one housingcomponent, in this case the rotor housing 20 a, and the baffle plate100.

Here, the baffle plate 100 has been inserted into the rotor housing 20a.

It is basically also contemplated that the housing cover of the screwcompressor 10 may also be used instead of the rotor housing 20 a. In theinserted and assembled state as shown in FIG. 2, the baffle plate 100has been bent as a result of the insertion into the rotor housing 20 a,such that the baffle plate 100 is held braced with a clamping action inthe rotor housing 20 a.

For this purpose, as shown in FIGS. 3 and 4, it is firstly the case thatfingers 102, specifically three fingers 102, are arranged on one side onthe baffle plate 100.

Secondly, the rotor housing 20 a has three baffle plate receivingapertures 104.

Here, the baffle plate receiving apertures 104 are arranged such thatthe two outer baffle plate receiving apertures 104 form a line, and thethird baffle plate receiving aperture 104 is arranged offset in relationto that line. The three baffle plate receiving apertures 104 are thusnot in alignment.

In other words, the middle of the three baffle plate receiving apertures104 is arranged outside the imaginary line that connects the two otherbaffle plate receiving apertures 104.

By use of the fingers 102, the baffle plate 100 is inserted into thebaffle plate receiving apertures 104.

This holding with clamping action is sufficient to securely fasten thebaffle plate 100 in the rotor housing 20 a.

Due to the offset of the middle baffle plate receiving aperture 104, thebaffle plate 100 is, owing to its stiffness, held firstly in bentfashion but also with a self-securing action, because the bending forcethat is furthermore exerted and the arrangement of the fingers 102ensure that the baffle plate 100 is held braced with clamping action inthe rotor housing 20 a by way of its fingers 102 in the baffle platereceiving apertures 104 of the rotor housing 20 a.

LIST OF REFERENCE SIGNS

-   10 Screw compressor-   12 Fastening flange-   14 Input shaft-   16 Screw-   18 Screw-   20 Housing-   20 a Rotor housing-   22 Oil-   24 Inlet connector-   26 Air filter-   28 Air inlet-   30 Valve insert-   32 Air feed channel-   34 Air outlet pipe-   36 Riser line-   38 Temperature sensor-   40 Holder for an air deoiling element-   42 Air deoiling element-   44 Filter screen or known filter or oil separation devices-   46 Air outlet opening-   48 Check valve-   50 Minimum pressure valve-   51 Air outlet-   52 Riser line-   54 Filter and check valve-   56 Nozzle-   58 Oil return line-   59 Oil drain screw-   60 Attachment piece-   62 Oil filter-   64 Oil filter inlet channel-   66 Thermostat valve-   68 Return line-   70 Bearing-   72 Nozzle-   76 Safety valve-   78 Bypass line-   80 Relief valve-   82 Oil level sensor-   100 Baffle plate-   102 Finger-   104 Baffle plate receiving apertures

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

What is claimed is:
 1. An arrangement for a screw compressor of autility vehicle, comprising: at least one housing component of the screwcompressor; and a baffle plate, wherein the baffle plate is, in anassembled state, inserted in a clamped fashion in the housing component.2. The arrangement as claimed in claim 1, wherein the housing componenthas at least three baffle plate receiving apertures, at least one baffleplate receiving aperture is arranged outside an imaginary line whichconnects the two other baffle plate receiving apertures, and the baffleplate has at least three fingers which, in the assembled state of thearrangement, are inserted in each case into a baffle plate receivingaperture assigned to the respective finger.
 3. The arrangement asclaimed in claim 2, wherein the housing component is a rotor housing ofthe screw compressor.
 4. The arrangement as claimed in claim 2, whereinthe housing component is a housing cover of the screw compressor.
 5. Thearrangement as claimed in claim 2, wherein a middle one of the threebaffle plate receiving apertures is arranged outside the imaginary linethat connects the two other baffle plate receiving apertures.
 6. Thearrangement as claimed in claim 2, wherein the fingers of the baffleplate are substantially in alignment in a non-inserted and non-assembledstate.
 7. The arrangement as claimed in claim 2, wherein the baffleplate is, in the inserted and assembled state, as a result of theinsertion of the fingers into the respectively associated baffle platereceiving apertures, bent such that the baffle plate is held braced withthe clamping action in the housing component.
 8. The arrangement asclaimed in claim 2, wherein the fingers of the baffle plate are allarranged at one edge of the baffle plate.